BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to a Polymerase Chain Reaction (PCR) apparatus, and
more particularly to a PCR apparatus for real-time quantifying of one or more fluorescent
signals.
2. Description of the Related Art
[0002] Polymerase Chain Reaction (PCR) is a technique for rapidly amplifying DNA. The principle
and main operation steps are as follows: (a) denaturing: a double-stranded DNA is
dissociated into single-stranded DNAs by incubation at 90°C to 95°C, and then the
single-stranded DNAs are used as templates for replication; (b) primer annealing:
when the temperature is lowered to an appropriate temperature, a primer will be attached
to a correct target gene position; and (c) primer extension: a reaction temperature
is corrected to 72°C, and the DNA polymerase successively attaches deoxy-ribonucleotide
triphosphate (dNTPs) to the primer to synthesize another strand of a new DNA fragment.
[0003] Nucleic acid amplification is repeated continuously through the three steps: denaturing,
primer annealing and primer extension. The number of target genes can be doubled in
each three-step operation. If the three-step operations are set to be cyclically performed
by 40 times, the number of target genes can be amplified by nearly 10
9 times, and a large number of target gene fragments can be obtained by the PCR
in vitro. Therefore, as one of molecular diagnostic techniques widely used in clinical diagnosis
at present, the PCR can be applied to items including diagnosis of genetic diseases,
diagnosis of pathogenic bacteria, diagnosis and prognosis evaluation of tumors and
cancers, basic research and the like, so that the PCR is also used as a technique
that is extensively used by the current clinical diagnosis.
[0004] In recent years, real-time polymerase chain reaction, also known as quantitative
real-time polymerase chain reaction (Q-PCR) (hereinafter referred to as real-time
PCR), has been developed in response to technique development requirements. Real-time
PCR and traditional PCR both use a thermal cycle step to amplify traced DNAs of the
target genes for amplification purposes, one difference being that for real-time PCR,
a non-specific fluorescent material or a specific fluorescent probe is added, after
each PCR amplification cycle, the DNA of a target gene is amplified and a fluorescent
signal is generated simultaneously, and then the fluorescent signal of a product is
detected and recorded; after PCR is completed, a graph is drawn according to a cycle
number and the fluorescent signals in order to obtain a reaction curve diagram which
perfectly shows the product generation of each cycle in PCR; and the reaction curve
diagram is analyzed through a built-in program to obtain a real-time quantitative
result.
[0005] A currently and commonly used non-specific fluorescent dye is SYBR Green I, which
binds to a minor groove of a DNA molecule to release fluorescence, so that the number
of PCR products generated in each cycle can be obtained by measuring the fluorescence
intensity at the end of the primer extension step of each cycle in the PCR process.
However, since the SYBR Green I can bind to all double-stranded DNAs, it is impossible
to distinguish specific products from non-specific products, so that the SYBR Green
I is relatively low in specificity for products, and sometimes false positive results
are obtained.
[0006] A currently and commonly used specific fluorescent probe is a TaqMan probe, which
is a synthetic oligonucleotide with the specificity for a target gene sequence. Different
fluorescent materials are labeled respectively at two ends of the oligonucleotide:
the molecule at the 5' end is called a reporter and the molecule at the 3' end is
called a quencher. If the specific probe is in a free state, the interaction between
the reporter and the quencher will quench the fluorescence of each other, so that
no fluorescence will be generated. However, when a PCR product is generated, after
the specific probe is hydrolyzed, the quencher loses the efficacy in quenching the
reporter, so that the fluorescence of the reporter can be detected. Since the specific
probe is the oligonucleotide specific only to the target gene, it would not bind to
other non-specific products. At present, the commonly used fluorescent dyes in combination
with the TaqMan probe include: FAM, VIC, HEX, ROX, CY3, CY5, CY5.5, JOE, TET, Texas
Red, TAMRA, NED, Quasar705, Alexa488, Alexa546, Alexa594, Alexa633, Alexa643 and Alexa680.
[0007] Each of these fluorescent dyes has its optimal absorption wavelength range and scattering
wavelength range, but most of the optimal absorption wavelength ranges and scattering
wavelengths of the above fluorescent dyes are often overlapped, so that when two or
more fluorescent dyes are needed to simultaneously quantify two or more different
target genes in the same test tube for the same specimen, fluorescent dyes that do
not produce a high signal crosstalk will be practically selected and combined for
use, and the obtained data is analyzed by a traditional data mode; and distinguishable
fluorescent signals are obtained in the end to facilitate the interpretation of the
results. The other method is such that only one target gene is tested in one test
tube at one time, but there are several test tubes to detect different target genes
of the same specimen; and the detection results of several detection targets in the
specimen are combined. Through this method, a situation in which the data cannot be
analyzed due to the fluorescent signal crosstalk can be avoided. The advantage of
the former method is that no matter how many target genes are tested, they can be
tested in the same test tube, so that there is less waste of consumables. However,
the disadvantage is that there are a plurality of sources of fluorescent signals,
which would cause a signal crosstalk phenomenon and results in errors in data analysis,
or an inability to effectively distinguish which target gene the signal crosstalk
part belongs to, thus it is easy to cause a misjudgment in the experimental results.
In the latter method, only one target gene is tested in one test tube, and a plurality
of test results are combined for analysis, so that the problem of signal crosstalk
can be effectively resolved indeed, and the accuracy of signal identification is much
higher than that of the former method However, it may consume many consumables, and
a relatively large amount of specimens are needed. At present, when a plurality of
target genes needs to be quantified for the same specimen, the latter method is often
used.
[0008] At present, most of the apparatuses used for real-time PCR in a laboratory often
use a temperature-controlled metal as a heater. Heating and cooling operations are
repeatedly performed based on the characteristics of rapid heating and cooling of
the temperature-controlled metal, so as to reach the reaction temperatures of three
steps: denaturing, primer annealing and primer extension. Furthermore, energy is transferred
to the reagents and the reactants (including fragments of the target genes) in the
test tube by heating the plastic-made reagent container, so as to achieve the efficacy
in amplifying signals of target genes and detecting their fluorescent signals. However,
such a machine that uses the temperature-controlled metal to repeatedly perform heating
and cooling is generally bulky. That is, to obtain effective temperature control,
the entire temperature control system must have a relatively large size and heat capacity
ratio. Furthermore, according to the design of the current machine, it takes most
of the time for the machine to wait for heating or cooling the temperature-controlled
metal to the reaction temperature. If the number of cycles required for a regular
test is about 30 to 35 cycles, it needs a reaction time of about two to three hours
for the conventional machine. As a result, it is difficult to shorten the reaction
time. Therefore, such a conventional machine cannot be applied to the test that the
result could be obtained within the extremely short period.
[0009] In order to alleviate the problems of the conventional apparatus, researchers have
applied real-time PCR to a microfluidic wafer technique. This technique has the advantage
that a microfluidic wafer can reduce the volume of the reagent or reactant and the
entire heat capacity ratio, and the reaction time can thus be shortened and the reagent
consumption can be reduced. However, because this technique still needs circulated
heating and cooling in three different temperature intervals, there is still a problem
of an extremely long heating and cooling time.
[0010] Another developed real-time PCR microfluidic wafer lacks the setting of repeated
heating and cooling of a heater, and uses a specially designed driving force to pressurize
the reactant and the reagent in a flow path, so that the reactant and the reagent
repeatedly flow through a specially processed and designed flow path with three different
temperature intervals to achieve amplification of the target gene and signal detection.
Real-time PCR performed using this technique can eliminate the time consumption caused
by heating and cooling, but the system for this technique needs to include a complicated
pressurization system and a hydraulic drive system. The hydraulic drive system is
also highly related to the volume viscosity of liquid, so that difficulties in the
manufacture and control of the system and instrument arise. Accordingly, the development
of this technique is indirectly limited.
[0011] Researchers have also developed another technique for performing real-time PCR using
a thermal convection cycle to solve the problems of high capacitance ratio and high
time consumption in conventional machines. This technique uses two heat sources with
different temperatures to heat the upper and lower ends of a closed test tube which
contains the reagent and the reactant. The reagent and the reactant are driven by
the temperature difference between the upper and lower ends to flow through the different
temperature intervals of the test tube, so as to perform real-time PCR. This technique
overcomes the time consumption caused by the repeated heating and cooling of the heater,
and does not need to drive the hydraulic circulation in the test tube by external
pressurization. However, because the heater is usually a piece of metal and its heat
capacity ratio cannot be reduced, the size of the machine cannot be minimized. Furthermore,
the complicated temperature control mechanism and the metal heating system also results
in the high manufacturing cost of the machine.
[0012] When multiple target genes or objects need to be quantified for the same specimen,
the above problems on the combination of fluorescent probes and the machine would
be more serious. That is, in order to obtain a highly reliable fluorescent signal
value, one target gene would be merely used in one test tube for one time in practice,
and a plurality of test results are combined for determination. If doing so, the test
for each specimen needs to use a plurality of test tubes. If the machine is one that
is usually used in a laboratory, or if the microfluidic wafer is repeatedly heated
and cooled at different temperature intervals, there still has problems on the consumption
of consumables and the requirement for more specimens in addition to the issue of
the longer test time. Even if the test is performed on the microfluidic wafer with
the special flow path design or on the apparatus for the real-time PCR test using
the thermal cycle, and the problem of the longer test time can be eliminated, the
issues of the consumption of consumables and the requirement for more specimens still
cannot be overcome.
[0013] In view of the above problems, the present invention discloses a PCR apparatus which
can overcome the problems of oversized dimension and time consumption caused by repeated
heating and cooling in the conventional machine and can simultaneously overcome the
problems of the consumption of consumables and the requirement for more specimens.
SUMMARY OF THE INVENTION
[0014] The present invention relates to a Polymerase Chain Reaction (PCR) apparatus for
real-time detecting of one or more fluorescent signals. The apparatus includes a reagent
container holding mechanism (or component) which is formed by a heat-resistant material.
The surface layer of the heat-resistant material may include a heat-resistant insulating
material or a conductive thin film, which is formed by coating with conductive material,
or both the heat-resistant insulating material and the conductive thin film. Furthermore,
the reagent container holding mechanism may have different structural designs according
to different external contours of reagent containers and different temperature control
conditions; and other conductive components such as a circuit board or conductive
metal component may be also incorporated to facilitate the operation. The heat-resistant
material may be metal or non-metal. If it is metal, the heat-resistant material may
be aluminum, copper, the alloy thereof or other heat-resistant metals. If it is non-metal,
the heat-resistant material may be glass, plastic, or ceramic. If the heat-resistant
material is metal, the metal may be coated with a layer of heat-resistant insulating
material, such as aluminum oxide, polytetrafluoroethylene or polyimide.
[0015] Regardless of the heat-resistant material being a metal or not, the surface of the
heat-resistant material would be coated with a conductive thin film to provide a specific
resistance value, which depends on the design of heating mechanism of the reagent
container holding mechanism. If the design of the heating mechanism only includes
a metal-made conductive material without other heating components, the surface layer
of the heat-resistant material of the apparatus disclosed by the present invention
would be coated with a conductive thin film. Because the conductive thin film has
specific resistance value, the heating mechanism starts to heat when receiving current.
On the contrary, if the heating mechanism is designed to include an electric heating
apparatus, such as a circuit board with an electric heating element welded thereon,
the reagent container holding mechanism can be started to heat after being electrified,
and thus the heat-resistant material no longer needs to be coated with a layer of
conductive thin film. The conductive material of the present invention may be: tin
oxide, indium oxide, zinc oxide, indium tin oxide, chromium, titanium, tantalum or
copper. The electric heating element of the present invention may be a resistor or
a printed circuit board (PCB) layout. According to the design of heating mechanism
disclosed by the present invention, the size of the heating mechanism may be greatly
reduced. Compared with a traditional PCR machine, the apparatus has more advantages
in size and derivativeness.
[0016] The portion, in contact with the reagent container, of the reagent container holding
mechanism is provided with at least one temperature sensor. The position and the number
of temperature sensors may depend on the position of the reagent container disposing
in the reagent container holding mechanism, at which temperature change can be easily
detected and the reaction in the reagent container would not be affected. The temperature
sensor is configured to monitor and report the temperature at the position.
[0017] The present invention also includes a power supply, a heat dissipation apparatus
and a processor. The power supply is configured to supply power for heating and cooling
of the reagent container holding mechanism and the operation of whole apparatus. The
heat dissipation apparatus is configured to cool the system. The processor is pre-loaded
with a program, so as to quantify and analyze one or more fluorescent signals by using
an algorithm. The algorithm may be one in which the parameters are set based on the
least square method.
[0018] In addition to the analysis of the fluorescent signals, the processor may be further
configured to: control the time points to start the power supply to heat the reagent
container holding mechanism, to start the heat dissipation apparatus, and to turn
on and/or off the light source of the system. The power supply is electrically connected
to the reagent container holding mechanism. More precisely, the connector of the power
supply may be electrically connected to the conductive thin film on the surface layer
of the reagent container holding mechanism, or electrically connected to other electric
heating element of the reagent container holding mechanism. When the power supply
starts to supply the power, the reagent container holding mechanism begins being heated
to a predetermined temperature, and in this case, the temperature sensor arranged
in the reagent container holding mechanism would start to detect the temperature and
report the temperature to the processor. When the temperature sensor detects that
the temperature of the reagent container holding mechanism meets the highest temperature
predetermined by the system for a predetermined period of time, the heat dissipation
apparatus is started to cool the reagent container holding mechanism to a low temperature
interval predetermined by the system. The installation position of the heat dissipation
apparatus or the position of the heat dissipation apparatus relative to the reagent
container holding mechanism is not specifically defined, as long as the temperature
of the apparatus may be rapidly and effectively lowered. In the temperature setting
of the present invention, the heating temperature interval of the reagent container
holding mechanism may be allowed to be 85°C to 130°C, and the cooling temperature
interval of the reagent container holding mechanism may be allowed to be 50°C to 75°C.
[0019] In one preferred embodiment of the present invention, the heat dissipation apparatus
may be a fan. Furthermore, a thermoelectric (TE) cooler or one or more fans may be
incorporated with the heat dissipation apparatus to achieve rapid and effective cooling.
The heat-resistant material constituting the reagent container holding mechanism may
also include a plurality of heat dissipation holes penetrating therethrough, so as
to accelerate heat dissipation.
[0020] The apparatus disclosed by the present invention is provided with at least one light
source, at least one spectrometer. The light source is configured to excite a fluorescent
dye or a fluorescent probe to generate detectable fluorescence. The apparatus disclosed
by the present invention also may be incorporated with a plurality of light sources
having different wavelengths for excitation. The beam emitted from the light source
may enter into the reagent container at a specific angle through a light illumination
lens, and excites the fluorescent material to generate the fluorescence. The generated
fluorescence passes through a fluorescence outlet and a light detection lens and then
enters into the spectrometer. The spectrometer processes the fluorescence into the
fluorescent signal in spectrum format and then the signal is sent to the processor
for analysis. The light source adopted in the present invention includes a light emitting
diode (LED), a laser, or other light sources having wavelengths being consistent with
the absorption wavelengths of the fluorescent dyes or fluorescent probes, and these
light sources also may be incorporated for use. The light illumination lens and the
light detection lens adopted in the present invention may be: biconvex lenses, plano-convex
lenses, doublet lenses, aspheric lenses, achromatic lenses, anastigmatic lenses, Fresnel
lenses, plano-concave lenses, biconcave lenses, positive/negative meniscus lenses,
axicons, gradient index lenses, micro-lens arrays, cylindrical lenses, waveguide elements,
diffractive optical elements, holographic optical elements, or a combination thereof.
The processor can control the time to turn on and turn off the light source, and also
can control whether the spectrometer starts to detect the fluorescent signal upon
the light source is turned on.
[0021] There is no specifically defined arrangement for the light source, the spectrometer,
the light illumination lens, the light detection lens or the reagent container holding
mechanism in the apparatus of the present invention, as long as the arrangement basically
ensures that the light source (and the light emitting path thereof) and the light
illumination lens are located at one side of the reagent container holding mechanism,
and the beam emitted from the light source can pass through the light illumination
lens and can be guided into the reagent container to effectively excite the fluorescent
dye or fluorescent probe of the reagent. In addition, the generated fluorescence can
be transmitted to the spectrometer through the light detection lens, followed by transmitting
the fluorescent signal in spectrum format, which is processed by the spectrometer,
into the processor for relevant signal analysis. In one preferred embodiment of the
present invention, the light source and the light illumination lens are located under
the reagent container holding mechanism, and the light detection lens and the spectrometer
are arranged to form a fictitious line, which is perpendicular to the other fictitious
line formed by the light source and the light illumination lens. In another preferred
embodiment disclosed by the present invention, the reagent container holding mechanism
may be provided with a fluorescence outlet on a fluorescence emitting path, so as
to facilitate the operation of the apparatus disclosed by the present invention.
[0022] According to the apparatus disclosed by the present invention, the detectable fluorescent
signal for the spectrometer is ranged from 340 nm to 850 nm. The emission wavelength
of the fluorescent dye or fluorescent probe used in the present invention should also
range from 340 nm to 850 nm, and the fluorescent dye includes, but is not limited
to: FAM, VIC, HEX, ROX, CY3, CY5, CY5.5, JOE, TET, SYBR, Texas Red, TAMRA, NED, Quasar705,
Alexa488, Alexa545, Alexa594, Alexa633, Alexa643 and Alexa680. Other fluorescent dyes
having emission wavelengths between 340 nm and 850 nm also may be applied in the present
invention.
[0023] The apparatus disclosed by the present invention may detect a plurality of target
genes or objects in the same reagent container. That is, one or more fluorescent dyes
or fluorescent probes are added to the same reagent container to perform the real-time
PCR, and the fluorescent signals for each reaction are collected. The fluorescent
signals are analyzed by the algorithm pre-loaded in the processor to achieve the qualitative
and quantitative results for the plurality of target genes or objects. When one or
more fluorescent dyes or fluorescent probes are added, signal crosstalk may occur
between the fluorescent signals. In order to effectively detect and identify two or
more fluorescent signals in the same reagent container in a real-time manner, firstly,
a standard fluorescence spectrum of the fluorescent dye or fluorescent probe to be
used is input into the algorithm which is pre-loaded in the processor, a standard
spectrum of the excitation light source used by the apparatus is also input into the
processor, and two spectrums are used as the standard values of the algorithm Subsequently,
a measured original fluorescent signal and the standard spectrum are calculated and
compared through the algorithm to obtain a fluorescent signal value proportional to
the concentration of the target genes. For example, if six different target genes
or objects are to be detected in the same reagent container (i.e., six different fluorescent
dyes or fluorescent probes need to be used), the standard spectrums of the six fluorescent
dyes or fluorescent probes should be input into the algorithm which is pre-loaded
in the processor, and the standard spectrum of the excitation light source is also
input into the algorithm which is pre-loaded in the processor, followed by performing
the real-time PCR. After completing the operation of the program, the processor may
receive the measured original spectrum data, and the original data are the superimposed
fluorescent signal of six fluorescent dyes or fluorescent probes. After the background
value is deducted, the individual duty ratios of six fluorescent signals in the fluorescent
spectrums of each PCR cycle are calculated using the algorithm. Real-time fluorescent
signal values of the individual fluorescent dyes or fluorescent probes can be separated
and obtained through the calculation. After conversion, qualitative and quantitative
results of six different target genes or objects can be obtained.
[0024] During the operation of the apparatus disclosed by the present invention, the power
supply is turned on at first, and the conductive material is then started to be electrified
to warm up the reagent container holding mechanism. The reagent container containing
the reactant and the reagent is disposed into the holding space of the reagent container
holding mechanism. Through rapid and repeated heating and cooling on the reagent container
holding mechanism, the reactant and the reagent start to undergo denaturing steps,
primer annealing steps, primer extension steps. At specific moment, the processor
turns on a light source switch, and the emitted excitation light enters into the reagent
container through the light illumination lens and excites the fluorescent material
in the container to emit fluorescence. The generated fluorescence passes through the
light detection lens and is received and processed into fluorescent signal in spectrum
format by the spectrometer. The signal is transmitted to the processor for signal
analysis. Finally, qualitative or quantitative analysis may be performed for the target
gene or object to be detected in the reagent container.
[0025] According to the apparatus disclosed by the present invention, the conductive thin
film or electric heating element is incorporated with the small-sized heating mechanism
to provide the rapid heating and cooling functions, so that the time for PCR is effectively
shortened. Meanwhile, the fluorescence values of one or more fluorescent signals may
be analyzed in a real-time manner through the built-in algorithm, so as to qualitatively
and quantitatively determine the target genes within a short time. In order to fulfill
the foregoing purpose, the preferred embodiment according to the present invention
is provided as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026]
Fig. 1 is a schematic diagram showing the component configuration of an apparatus
in one preferred embodiment of the present invention;
Figs. 2-1 and 2-2 are schematic diagrams showing a reagent container holding mechanism,
a heat dissipation hole and a temperature sensor in the preferred embodiment of the
present invention;
Fig. 2-3 is a top view of the reagent container holding mechanism in the preferred
embodiment of the present invention;
Fig. 2-4 is a side view of the reagent container holding mechanism in the preferred
embodiment of the present invention;
Fig. 2-5 is a top view of the layers of the first and the second substrate in the
preferred embodiment of the present invention;
Fig. 3 is a diagram showing the original fluorescent signals in the preferred embodiment
of the present invention;
Fig. 4 is a diagram showing the analytic result for the fluorescent signals in the
preferred embodiment of the present invention;
Fig. 5-1 is a schematic diagram showing a reagent container holding mechanism in another
preferred embodiment of the present invention;
Fig. 5-2 is a top view of the reagent container holding mechanism in another preferred
embodiment of the present invention;
Fig. 6-1 is a schematic diagram showing a reagent container holding mechanism in another
preferred embodiment of the present invention; and
Fig. 6-2 is a schematic diagram showing a reagent container holding mechanism in another
preferred embodiment of the present invention.
PREFERRED EMBODIMENT OF THE PRESENT INVENTION
[0027] The structure and function of one preferred embodiment of the present invention will
be described in detail below with reference to the accompanying drawings. In addition,
in this description, the position of a mechanism or positions of its parts are described
as "before," "after," "left," "right," "above," "below," etc., which correspond to
the spatial relationship when a user operates the present preferred embodiment.
[0028] Please refer to Fig. 1, which shows the component configuration for constituting
an apparatus (1) in one preferred embodiment of the present invention. The apparatus
(1) in the preferred embodiment of the present invention includes a reagent container
holding mechanism (10), a first optical element (30), a light source (40), a second
optical element (50), a spectrometer (60), a fan (70), a thermoelectric cooler (80),
a processor (90) and a power supply (100). The reagent container holding mechanism
(10) is configured to deposit a reagent container (20) and provide a space (109, referring
to Fig. 2-3) for heating the reagent and the reactant, and the power supply (100)
is electrically connected to the reagent container holding mechanism (10). The fan
(70) and the thermoelectric cooler (80) are configured to electrically connect to
the power supply (100) to cool the reagent container holding mechanism (10). In addition,
the first and the second optical elements (30, 50) include but is not limited to biconvex
lens, plano-convex lens, doublet lens, aspheric lens, achromatic lens, anastigmatic
lens, Fresnel lens, plano-concave lens, biconcave lens, positive/negative meniscus
lens, axicon, gradient index lens, microlens array, cylindrical lens, diffractive
optical element, waveguide element, holographic optical element, mirror, fiber and
prism.
[0029] Please refer to Figs. 2-1 to 2-5, which show the reagent container holding mechanism
(10) in the preferred embodiment of the present invention. The reagent containing
holding mechanism (10) includes a first substrate (101) having a first concave surface
(1011), a second substrate (102) having a second concave surface (1021), a first metal
sheet (103), and a second metal sheet (104). The first substrate (101) has a first
heat dissipation hole (105) and a second heat dissipation hole (107) for the purpose
of heat dissipation, and the first substrate (101) also has a first fluorescence outlet
(106) and a first temperature sensor (108). The first temperature sensor (108) is
configured to detect the temperature of the reagent container holding mechanism (10)
and report the temperature to the processor (90). The second substrate (102) only
has a first heat dissipation hole (105) and a second heat dissipation hole (107).
[0030] The first substrate (101) and the second substrate (102) are in mutually parallel
arrangement so that the first concave surface (1011) and the second concave surface
(1021) are mutually coupled in a mode of being perpendicular to a horizontal plane,
and form a space (109) for placement of the reagent container (20). The outer wall
of the reagent container (20) is in thermal contact with the first concave surface
(1011) and the second concave surface (1021). There is no special limit to the contours
of the first concave surface (1011) and the second concave surface (1021), as long
as the contours may substantially be consistent with the reagent container (20). In
the present embodiment, since the reagent container (20) is a test tube, the contour
of the space (109) formed by facing the first concave surface (1011) to the second
concave surface (1021) for placement of the reagent container (20) is the contour
of the exterior surface of the test tube. The first metal sheet (103) and the second
metal sheet (104) are sandwiched between the first substrate (101) and the second
substrate (102), and are parallel to the first substrate (101) and the second substrate
(102). Furthermore, the first metal sheet (103) and the second metal sheet (104) are
located at two ends of the first substrate (101) and the second substrate (102). The
first metal sheet (103) and the second metal sheet (104) are connected to the power
supply (100).
[0031] In the present embodiment, the base material of the first substrate (101) and the
second substrate (102) is aluminum. The base material is firstly anodized, and plated
with a layer of aluminum oxide followed by plating with a layer of the conductive
thin film. The material of the conductive thin film of the present embodiment may
be: tin oxide, indium oxide, zinc oxide, indium tin oxide, chromium, titanium, tantalum
or copper. The material of the first metal sheet (103) and the second metal sheet
(104) is copper in the present embodiment.
[0032] Please refer to Fig. 1, in the present embodiment, the light source (40) is a laser
diode, which is configured to excite fluorescent dyes or fluorescent probes to generate
detectable fluorescence. If needed, the light source (40) may also be replaced with
a set of laser lights or a LED. The first optical element (30) is configured to guide
the beam emitted from the light source (40) to the reagent container (20). In the
present embodiment, the reagent container (20) has been already placed in the reagent
container holding mechanism (10). The light source (40) and the first optical element
(30) are located under the reagent container (20) and are arranged vertically together
with the reagent container (20). Furthermore, the first optical element (30) is located
between the light source (40) and the reagent container (20). Such an arrangement
ensures that the excitation light emitted from the light source (40) is guided by
the first optical element (30) to the bottom of the reagent container (20), so as
to excite the fluorescent dye or fluorescent probe in the reagent container (20).
[0033] Please refer to Fig. 1, in the present embodiment, the second optical element (50)
is configured to transmit the generated fluorescence to the spectrometer (60). The
second optical element (50) can include an optical filter (51) located between the
reagent container holding mechanism (10) and the spectrometer (60), and the optical
filter (51) is configured to filter out the light exceeding the wavelength range of
the one or more fluorescent signals. The spectrometer (60) process the fluorescence
into the fluorescent signal in spectrum format, and then transmits the signal to the
processor (90) for signal analysis. The second optical element (50) and the spectrometer
(60) are located at the side, which is closed to the first substrate (101) of the
reagent container holding mechanism (10), and the second optical element (50), the
spectrometer (60), and the first fluorescence outlet (106) need to be horizontally
arranged as much as possible, so that the excited fluorescent signal in the reagent
container (20) may sequentially pass through the first fluorescence outlet (106) and
the second optical element (50), whereupon it is emitted straightly and detected by
the spectrometer (60). In the present embodiment, the second optical element (50)
and the spectrometer (60) are located at one side of the reagent container holding
mechanism (10), and a fictitious line formed by the arrangement of the second optical
element (50) and the spectrometer (60), and the other fictitious line formed by the
arrangement of the first optical element (30) and the light source (40) are perpendicular.
[0034] Please refer to Fig. 1, in the present embodiment, the fan (70) is a heat dissipation
apparatus, is used to incorporated with the thermoelectric cooler (80), and the position
of the fan (70) is not specified. In the present embodiment, the fan (70) is located
at the side, which is closed to the second substrate (102) of the reagent container
holding mechanism (10), and the thermoelectric cooler (80) is located above the fan
(70). When the apparatus (1) starts to be cooled, the first heat dissipation hole
(105) and the second heat dissipation hole (107) will dissipate heat synergistically.
The apparatus (1) of the present embodiment includes a processor (90), and the least
square method-based algorithm for fluorescent signal analysis is pre-loaded in the
processor (90). In the present embodiment, a standard spectrum of the fluorescent
dye or fluorescent probe to be used and a spectrum of the light source (40) should
be input for the purpose of subsequent data analysis.
[0035] The processor (90) also receives the signal of the first temperature sensor (108).
When the temperature of the reagent container holding mechanism (10) exceeds the temperature
range set by the system, the fan (70) and the thermoelectric cooler (80) are turned
on to cool the reagent container holding mechanism (10). When the temperature of the
reagent container holding mechanism (10) is lower than the temperature range set by
the system, the power supply (100) starts to heat the apparatus (1). In the present
embodiment, in order to be consistent with heating rate control, the processor (90)
may further control the first metal sheet (103) and the second metal sheet (104) to
be simultaneously electrified and heated, or control only the first metal sheet (103)
or the second metal sheet (104) to be heated.
[0036] The present embodiment also includes a power supply (100), which is configured to
provide power required by the entire apparatus (1). When the power supply (100) is
turned on, current is transmitted to the first metal sheet (103) and the second metal
sheet (104). Because the material of the first metal sheet (103) and the second metal
sheet (104) is copper, the current can be conducted to the portions of the first substrate
(101) and the second substrate (102) in contact with the first metal sheet (103) and
the second metal sheet (104).Because the surface layers (101a, 102a) of the first
substrate (101) and the second substrate (102) are coated with conductive thin films
(101b, 102b) having specific resistance values, the reagent container holding mechanism
(10) starts to be heated to a temperature interval of 95°C to 100°C which is a heating
temperature interval set in the present embodiment. Furthermore, in the present embodiment,
the processor (90) is programmed so that the reagent container holding mechanism (10)
may be maintained within this heating temperature interval for about 6 s to 15 s to
perform the step of the real-time PCR in the reagent container (20). Subsequently,
the processor (90) may be programmed to start the fan (70) and/or the thermoelectric
cooler (80) to start cooling the reagent container holding mechanism (10) to a temperature
interval of 60°C to 62°C, which is a low temperature interval set in the present embodiment.
In the present embodiment, the processor (90) is programmed so that the reagent container
holding mechanism (10) may be maintained within this low temperature interval for
about 1 s to 5 s to perform the step of the real-time PCR in the reagent container
(20). In order to provide effective and sufficient reaction time and temperature,
the processor (90) also controls the temperature of the reagent container holding
mechanism (10) to be in the repeated cycles of the heating temperature interval and
the low temperature interval until the reaction is ended. When the temperature of
the reagent container holding mechanism (10) stably increases and decreases in this
manner, the temperatures of the reactant and the reagent in the reagent container
(20) can reach three temperature intervals required in real-time PCR.
[0037] When real-time PCR is started, the reagent and the reactant, neighboring to the reagent
container (20) and the reagent container holding mechanism (10), are heated at first.
When the reactant and the reagent close to the reagent container (20) are heated to
95°C, the reactant and the reagent at this portion start to process a denaturing step,
and reach to the temperatures for primer annealing and primer extension by controlling
the temperature cycling of the reagent container holding mechanism (10).
[0038] The processor (90) then turns on the switch of the light source (40), and the emitted
excitation light enters into the reagent container (20) through the first optical
element (30) to excite the fluorescent material in the reagent container (20) to emit
fluorescence. The generated fluorescence passes through the second optical element
(50), and the spectrometer (60) processed it into the original fluorescent signal.
The original fluorescent signal is then transmitted to the processor (90). After processing
by the least-square-method-based algorithm which is pre-loaded in the processor and
removing the signal values of background light, the data and the pre-input standard
spectrum of the fluorescent dye or fluorescent probe are subjected to verification
analysis. Finally, the intensity of each fluorescent signals can be obtained, and
the qualitative or quantitative analysis may be performed for the target gene or object
to be detected in the reagent container (20) via conversion.
[0039] Through the settings in the present embodiment, if four fluorescent probes at different
concentrations are respectively added to four reagent containers (20), and each reagent
container (20) contains four fluorescent probes FAM, VIC, Alexa594 and Alexa647 at
the same concentration, the mixed original fluorescent data from four reagent containers
(20) can be obtained through the implementation of the apparatus (1) at first (as
shown in Fig. 3). Subsequently, through the built-in least-square-method-based algorithm;
the concentration of each fluorescent probe in four reagent containers (20) may be
obtained by analysis (as shown in Fig. 4).
[0040] Referring to Figs. 5-1 and 5-2, in another preferred embodiment, another reagent
container holding mechanism (210) can be used to replace the above reagent container
holding mechanism (10), and other configurations of the apparatus are the same as
those in the previous embodiment. The reagent container holding mechanism (210) includes
a third substrate (201), a fourth substrate (202) and an insulating sheet (204). The
third substrate (201) has a temperature sensor (205) which is configured thereon to
detect the temperature of the reagent container holding mechanism (210) and report
the temperature to the processor (90). The third substrate (201) and the fourth substrate
(202) are made of the same heat-resistant substrate, which is only bent at specific
angles and symmetrically arranged, and the bent portion forms a reagent container
receiving place (203). The contour of the reagent container receiving place (203)
is not particularly limited, as long as the contour may accommodate the reagent container
(220). In the present embodiment, because the reagent container (220) is a test tube,
the contour of the reagent container holding place (203) is the same as that of the
exterior surface of the reagent container (220). The insulating sheet (204) is included
between the third substrate (201) and the fourth substrate (202), and the third substrate
(201) and the fourth substrate (202) are respectively connected to the power supply
(100).
[0041] In the present embodiment, the base material of the third substrate (201) and the
fourth substrate (202) is aluminum. The base material is anodized and plated with
a layer of aluminum oxide, followed by plating a layer of conductive thin film. The
material of the conductive thin film elected for the present embodiment may be: tin
oxide, indium oxide, zinc oxide, indium tin oxide, chromium, titanium, tantalum or
copper. The power supply (100) is electrically connected to the third substrate (201)
and the fourth substrate (202). The third substrate (201) and the fourth substrate
(202) are respectively an anode and a cathode, which are separated by the insulating
sheet (204), to ensure they are unable to be in contact.
[0042] Referring to Figs. 6-1 and 6-2, in another preferred embodiment, another reagent
container holding mechanism (310) may also be used to replace the above reagent container
holding mechanism (10), and other components and configurations of the apparatus (1)
are the same as those in the aforementioned embodiment. The reagent container holding
mechanism (310) includes a fifth substrate (301) having a third concave surface (3011),
a sixth substrate (302) having a fourth concave surface (3021), a first circuit board
(303) and a second circuit board (304). The fifth substrate (301) has a third heat
dissipation hole (305) and a fourth heat dissipation hole (307) thereon for heat dissipation.
The fifth substrate (301) also has a second fluorescence outlet (306) and a second
temperature sensor (308). The second temperature sensor (308) is configured to detect
the temperature of the reagent container holding mechanism (310) and report the temperature
to the processor (90). The sixth substrate (302) only has a third heat dissipation
hole (305) and a fourth heat dissipation hole (307).
[0043] The fifth substrate (301) and the sixth substrate (302) are arranged mutually in
parallel to cause the third concave surface (3011) and the fourth concave surface
(3021) to be mutually coupled in a mode of being perpendicular to a horizontal plane
and form a space for placement of the reagent container (20). The outer wall of the
reagent container (20) (not shown in Figs. 6-1 and 6-2) is in thermal contact with
the third concave surface (3011) and the fourth concave surface (3021). The contours
of the third concave surface (3011) and the fourth concave surface (3021) are not
particularly limited, as long as the contours are consistent with the contour of the
reagent container (20). In the present embodiment, because the reagent container (20)
is a test tube, the surrounding wall of the space formed by coupling the third concave
surface (3011) to the fourth concave surface (3021) for placement of the reagent container
(20) is the contour of the exterior surface of the test tube. The first circuit board
(303) and the second circuit board (304) are sandwiched within and are parallel to
the fifth substrate (301) and the sixth substrate (302). Furthermore, the first circuit
board (303) and the second circuit board (304) are respectively located at two opposite
ends of the fifth substrate (301) and the sixth substrate (302). The front and rear
surfaces of each of the first circuit board (303) and the second circuit board (304)
are respectively welded with a resistor (309), and the first circuit board (303) and
the second circuit board (304) are jointed with the fifth substrate (301) and the
sixth substrate (302). The first circuit board (303) and the second circuit board
(304) are also connected to the power supply (100). In the present embodiment, the
base material of the fifth substrate (301) and the sixth substrate (302) is aluminum.
The base material is anodized and plated with a layer of aluminum oxide.
[0044] When the power supply (100) is turned on, current is transmitted to the first circuit
board (303) and the second circuit board (304). At this moment, the resistor (309)
is electrified and the temperature thereof starts to increase, and drives the temperature
of the fifth substrate (301) and the sixth substrate (302) to increase accordingly.
Therefore, when the temperature of the reagent container holding mechanism (310) increases
to a temperature interval of 95°C to 100°C, real-time PCR is started. The second temperature
sensor (308) detects the temperature of the reagent container holding mechanism (310)
and reports the temperature to the processor (90). When the temperature exceeds a
heating temperature interval set by the system, the third heat dissipation hole (305)
and the fourth heat dissipation hole (307) would facilitate the cooling effect by
the fan (70) and the thermoelectric cooler (80). After a fluorescent signal is generated
by real-time PCR, the fluorescence emits through the fluorescence outlet (306) and
the second optical element (50), and is detected by the spectrometer (60).
1. A Polymerase Chain Reaction (PCR) apparatus (1) for real-time detecting and quantifying
one or more fluorescent signals in a reagent container (20), wherein the reagent container
(20) is configured to contain a reactant and a reagent containing one or more fluorescent
probes or fluorescent dyes, the PCR apparatus (1)
characterized by comprising:
a reagent container holding mechanism (10) configured to accommodate the reagent container
(20);
a light source (40) located at one side of the reagent container holding mechanism
(10), wherein a light emitted by the light source (40) enters into the reagent container
(20) and excites the one or more fluorescent probes or fluorescent dyes to generate
fluorescence;
a spectrometer (60) located at one side of the reagent container holding mechanism
(10) and configured to detect one or more fluorescent signals of the fluorescence;
and
a processor (90) pre-loaded with an algorithm to quantify the one or more fluorescent
signals, and configured to control the time points of the heating and cooling periods
of the reagent container holding mechanism (10), and to turn on and turn off the light
source (40).
2. The PCR apparatus (1) according to Claim 1,
characterized in that
the reagent container holding mechanism (10) is configured to start heating by electrifying
to increase the temperature of the reagent container (20);
the processor (90) is configured to control the temperature of the reagent container
holding mechanism (10) to be circulated between a first temperature interval and a
second temperature interval to perform PCR using the reactant and the reagent; and
the one or more fluorescent signals detected by the spectrometer (1) are transmitted
to the processor (90) for analysis.
3. The PCR apparatus (1) according to Claim 1 or 2,
characterized in that
the PCR apparatus (1) further comprises a heat dissipation apparatus (70, 80) and
a temperature sensor (108, 205, 308) which is located at one side of the reagent container
holding mechanism (10) and is configured to measure the temperature of the reagent
container holding mechanism (10);
when the temperature of the reagent container holding mechanism (10) detected by the
temperature sensor (108, 205, 308) exceeds the first temperature interval, the temperature
sensor (108, 205, 308) feeds the information back to the processor (90), and the processor
(90) sends a first signal to the heat dissipation apparatus (1) to lower the temperature;
and
when the temperature of the reagent container holding mechanism (10) detected by the
temperature sensor (108, 205, 308) is lower than the second temperature interval,
the temperature sensor (108, 205, 308) feeds the information back to the processor
(90), and the processor (90) sends a second signal to the reagent container holding
mechanism (10) to start heating by electrifying.
4. The PCR apparatus (1) according to any one of Claims 1 to 3, characterized in that the reagent container holding mechanism (10) is formed by a heat-resistant material,
the temperature of the reagent container holding mechanism (10) is measured in a real-time
manner, and the heat dissipation apparatus (70, 80) is one selected from the group
consisting of one or more fans (70), one or more thermoelectric (TE) coolers (80)
and the combination thereof.
5. The PCR apparatus (1) according to any one of Claims 1 to 4, characterized in that the PCR apparatus (1) further comprises a first optical element (30) which is located
between the reagent container holding mechanism (10) and the light source (40), and
is capable of guiding the light to the reagent container (20) and to excite the one
or more fluorescent probes or fluorescent dyes to generate the fluorescence, and the
first optical element (30) and the light source (40) are sequentially arranged under
the reagent container holding mechanism (10).
6. The PCR apparatus (1) according to any one of Claims 1 to 5, characterized in that the PCR apparatus (1) further comprises a second optical element (50) which is located
between the reagent container holding mechanism (10) and the spectrometer (60), and
is configured to collect the fluorescence, and guide the fluorescence to the spectrometer
(60), and the second optical element (50) and the spectrometer (60) are located on
the same horizontal plane.
7. The PCR apparatus (1) according to any one of Claims 1 to 6, characterized in that each of the first and the second optical elements (30, 50) is one selected from the
group consisting of a biconvex lens, a plano-convex lens, a doublet lens, an aspheric
lens, an achromatic lens, an anastigmatic lens, a Fresnel lens, a plano-concave lens,
a biconcave lens, a positive/negative meniscus lens, an axicon, a gradient index lens,
a microlens array, a cylindrical lens, a diffractive optical element, a waveguide
element, a holographic optical element, a mirror, a fiber and a prism.
8. The PCR apparatus (1) according to any one of Claims 1 to 7, characterized in that the reagent container holding mechanism (10) is formed by: a first substrate (101)
having a first concave surface (1011), a second substrate (102) having a second concave
surface (1021), a first conductive component (103) and a second conductive component
(104), the first and the second conductive components (103, 104) are disposed at two
opposite ends of the first substrate (101) and sandwiched between the first and the
second substrates (101, 102), and the first concave surface (1011) is faced to the
second concave surfaces (1021) to form a space (109) to accommodate the reagent container
(20).
9. The PCR apparatus (1) according to any one of Claims 1 to 8,
characterized in that
the first conductive component (103) and the second conductive component (104) are
metal sheets or printed circuit boards (PCBs),
when the first conductive component (103) and the second conductive component (104)
are the metal sheets, each of the first substrate (101) and the second substrate (102)
has a surface layer (101a, 102a) having a conductive thin film (101b, 102b) thereon,
and the conductive thin film (101b, 102b) is formed of a material being one selected
from the group consisting of tin oxide, indium oxide, zinc oxide, indium tin oxide,
chromium, titanium, tantalum or copper, and
when the first conductive component (103) and the second conductive component (104)
are the printed circuit boards (PCBs), the printed circuit boards (PCBs) further contain
one or more electric heating elements being a resistor or a PCB layout.
10. The PCR apparatus (1) according to any one of Claims 1 to 9, characterized in that the first substrate (101) and the second substrate (102) are in parallel arrangement
so that the first concave surface (1011) and the second concave surface (1021) are
mutually coupled in a direction roughly perpendicular to the horizontal plane along
corresponding coupling surfaces and to form the reagent container holding mechanism
(10).
11. The PCR apparatus (1) according to any one of Claims 1 to 10, wherein the first substrate
(101) has a fluorescent signal outlet window (106), and the first substrate (101)
is located between the second substrate (102) and the spectrometer (60).
12. The PCR apparatus (1) according to any one of Claims 1 to 11, characterized in that the reagent container holding mechanism (210) is formed by a first substrate (201),
a second substrate (202) and an electrical insulating material (204), the first and
the second substrates (201, 202) are formed of a heat resistant material and bent
into a specific shape, the first substrate (201) is combined with the second substrate
(202) with mirror-symmetry, and the electrical insulating material (204) is arranged
between the first substrate (201) and the second substrate (202).
13. The PCR apparatus (1) according to any one of Claims 1 to 12, characterized in that the reagent container holding mechanism (310) is formed by a heat-resistant material
(301, 302) having one or more heat dissipation holes (305, 307), the heat-resistant
material (301, 302) is a metal capable of rapidly conducting heat being selected from
the group consisting of an aluminum sheet, a copper sheet and an alloy thereof, the
surface layer of the heat-resistant material (301, 302) contains a heat-resistant
insulating material being one selected from the group consisting of aluminum oxide,
polytetrafluoroethylene and polyimide.
14. The PCR apparatus (1) according to any one of Claims 1 to 12, wherein the heat-resistant
material (301, 302) is a non-metal being one selected from the group consisting of
glass, plastic and ceramic.
15. The PCR apparatus (1) according to any one of Claims 1 to 14, characterized in that the algorithm is the least square method-based algorithm.
16. The PCR apparatus (1) according to any one of Claims 1 to 15,
characterized in that
the light source (40) is one selected from the group consisting of a light emitting
diode (LED), a laser source, multiple LEDs of different wavelength, multiple laser
sources of different wavelength, and the combination thereof,
the one or more fluorescent probes or fluorescent dyes have the wavelength between
340 nm and 850 nm and are: FAM, VIC, HEX, ROX, CY3, CY5, CY5.5, JOE, TET, SYBR, Texas
Red, TAMRA, NED, Quasar705, Alexa488, Alexa546, Alexa594, Alexa633, Alexa643, or Alexa680,
and
the detection range of the spectrometer (60) is between 340 nm and 850 nm.
17. The PCR apparatus (1) according to any one of Claims 1 to 16, characterized in that the processor (90) is configured to control the light source (40) to be turned on
or turned off at a specific time interval, and the spectrometer (60) and the light
source (40) are turned on to synchronously detect the one or more fluorescent signals.
18. The PCR apparatus (1) according to any one of Claims 1 to 17, characterized in that the PCR apparatus (1) further comprises an optical filter (51) located between the
reagent container holding mechanism (10) and the spectrometer (60), and the optical
filter (51) is configured to filter out the light exceeding the wavelength range of
the one or more fluorescent signals.
19. The PCR apparatus (1) according to any one of Claims 1 to 18, characterized in that the first temperature interval is 85°C to 130°C, and the second temperature interval
is 50°C to 75°C.
20. The PCR apparatus (1) according to any one of Claims 1 to 19, characterized in that the PCR has a third temperature interval different from the first temperature interval
and the second temperature interval, and the processor (90) is configured to control
the temperature of the reagent container holding mechanism (10) to repeatedly increase
and decrease in the cycle of the first temperature interval, the second temperature
interval and the third temperature interval.